The invention relates to a portable field water purifier. The portable field water purifier comprises a water container, a combined filtering module is arranged in the water container, a pressure device is connected with the upper end of the water container, a water inlet with an external thread is formed in the water container, and the water container is further provided with a detachable threaded connector used for conveniently changing the combined filtering module. A solar power storage battery and a water containing cup which is matched with the solar power storage battery in a threaded mode are connected with the water container, and an ultraviolet disinfection device is arranged in the water containing cup. The portable field water purifier is compact in structure and convenient to maintain; the solar power storage battery is installed at the upper end so that a safety accident caused by water leakage cannot happen; the combined filtering module is convenient to change; a gas uniflow hole plug and a reverse osmosis (RO) membrane are additionally arranged for preventing the situation that the upper pollution is caused by backflow, and secondary pollution cannot be caused; a lamp bulb and a USB interface are additionally arranged, so that the water purifier is more suitable for being used in the field; the water purifier is of a detachable structure and is convenient to clean and carry.